When suitable ships for a shipping service along a specified sailing route are selected from available ships, a cost that will be incurred by each available ship traversing the sailing route is usually considered. For example, it is described in paragraph 0027 of JP Hei-8-272402A that suitable ships for a shipping service are selected based on a cost of each ship including a cost of chartering the ship. According to the invention disclosed JP Hei-8-272402A, ships with comparatively inexpensive cost of chartering are selected for the shipping service, whereby costs incurred for using the shipping service are kept down.
Cost of a voyage varies depending on fuel cost required for the voyage of a ship as well as a cost of chartering the ship. For example, when plural ships are available to sail a specified sailing route and fuel consumption rates of the ships are different from each other, if a ship whose cost of chartering is inexpensive but has a high fuel consumption rate, a quantity of fuel required for the voyage becomes large, and fuel cost required for the voyage increases a total cost of the voyage. In recent years, crude oil prices have frequently soared. In this situation, high fuel consumption and increased fuel cost may cause a serious problem in maintaining businesses of companies providing shipping services.